Problem: $-2bc - 10c - 10d + 6 = 3c - 5d + 5$ Solve for $b$.
Answer: Combine constant terms on the right. $-2bc - 10c - 10d + {6} = 3c - 5d + {5}$ $-2bc - 10c - 10d = 3c - 5d - {1}$ Combine $d$ terms on the right. $-2bc - 10c - {10d} = 3c - {5d} - 1$ $-2bc - 10c = 3c + {5d} - 1$ Combine $c$ terms on the right. $-2bc - {10c} = {3c} + 5d - 1$ $-2bc = {13c} + 5d - 1$ Isolate $b$ $-{2}b{c} = 13c + 5d - 1$ $b = \dfrac{ 13c + 5d - 1 }{ -{2c} }$ Swap the signs so the denominator isn't negative. $b = \dfrac{ -{13}c - {5}d + {1} }{ {2c} }$